#include <bits/stdc++.h>
using namespace std;
int main() {
  double m;
  cin >> m;
  double box = 0;

  while (true) {
    double k;
    cin >> k;
    if (-1 == k)
      break;
    else
      box += k;
  }
  cout << int(box / m);
  int k;
  return 0;
}